1. Field of the Invention
The present invention relates to an apparatus to close the door of a refrigerator, and more particularly to an apparatus to close the door of a refrigerator, which is adapted to automatically close the door when the door is opened at a predetermined angle or less, and to maintain the door at a predetermined angle when the door is opened at an angle larger than the predetermined angle, and which is adapted to control the maximum opening angle of the door.
2. Description of the Related Art
In general, a refrigerator includes a freezing compartment, a refrigerating compartment, and a door to close the freezing compartment and the refrigerating compartment. Such a refrigerator is a home electric appliance, which is intended to generate cool air to freeze food in the freezing compartment and to keep food in the refrigerating compartment in a fresh state, thereby allowing food liable to spoil to be preserved for a long period of time. In such a refrigerator, a door serves to shield inside air in the freezing and refrigerating compartments from the outside air.
Where a door of a refrigerator is inadvertently maintained in a state of being opened after use of the refrigerator, cool air in the freezing or refrigerating compartment leaks outside therefrom, thereby causing excessive loss of electric power and spoiling of food stored in the affected compartments. To overcome this disadvantage, many attempts have been made to provide a refrigerator which is designed to enable its door to be automatically closed when a user releases the door, after the door is opened within a predetermined range of rotating angle.
Referring to FIGS. 1 to 4, there is shown a conventional apparatus to close the door of a refrigerator, which is adapted to enable the door to be automatically closed. Such a conventional apparatus will now be described with reference to FIGS. 1 to 4.
FIG. 1 shows a large-sized refrigerator, for which demand is increasing these days. The refrigerator includes a freezing compartment and a refrigerating compartment defined in a cabinet at its left and right sides. The refrigerator further includes a pair of leg parts 101 disposed under the cabinet. To close the freezing and refrigerating compartments, the refrigerator is provided with a pair of doors 102 and 103, which are pivotally coupled to the leg parts 101 to be opened and closed forwardly.
FIG. 2 is an exploded perspective view showing the circled portion “A” in FIG. 1. As shown in FIG. 2, the door 103 is provided at its right and lower end with a hinge hole 201 into which a hinge shaft 203a, formed at a hinge shaft bracket 203, is rotatably fitted at its one end. The hinge shaft bracket 203 is joined to the lower end of the door 103 by a fastening element such as a bolt. A hinge hole bracket 202 is joined to the right and lower end of the cabinet 100, i.e., a right leg part 101, by bolts. The hinge hole bracket 202 includes an extension portion 202a, which is bent forward. The extension portion 202a is provided with a hinge hole 202b into which the other end of the hinge shaft 203a is rotatably inserted. The extension portion 202a is provided around the hinge hole 202b with a cam-riser-low 202c, and the hinge shaft bracket 203 is provided around the hinge shaft 203a with a cam-riser-up 203b, which is engaged with the cam-riser-low 202c. 
An operation of the apparatus to dose a refrigerator door will now be described with reference to FIGS. 3 and 4.
FIG. 3 shows the circled portion “A” in FIG. 1, in which the door 103 is closed, and FIG. 4 shows the circled portion “A” in FIG. 1, in which the door 103 is somewhat open, i.e., rotated, and thus somewhat raised by the cam mechanism 202c and 203b. In this state, when a user releases the door 103, the door 103 is automatically closed by its own weight with the help of the cam mechanism, and thus returned to the position shown in FIG. 3. That is, the door 103 is automatically closed without any additional external force.
However, such a conventional apparatus to dose a refrigerator door which utilizes the above cam mechanism 202c and 203b, has disadvantages as follows. First, since the cam-riser-low 202c and the cam-riser-up 203b are in frictional contact with each other at their facing slanted cam faces during rotation of the door, the slanted cam faces of the cam mechanism become worm. Furthermore, because of the configuration of the cam mechanism 202c and 203b, though the door 103 is automatically closed by the cam mechanism when the door 103 is opened within a range of about 0 to 45 degrees, the door 103 must be rotated within the range of 0 to 45 degrees by an external force of a user when the door is rotated beyond the range of 0 to 45 degrees. In addition, since the door 103 is typically set to be rotated to the maximum rotation angle of 235 degrees, the door cannot be maintained in place at a rotation angle other than the maximum rotation angle. Since the door is raised during its opening operation due to the configuration of the cam mechanism, a user must apply the door with additional external force. Finally, since the door is not provided with a mechanism to absorb shock generated when the door is closed, there is a risk that articles stored on shelves of the door may fall down or drop from the shelves due to shock when the door is quickly closed.